Climbing film heat exchange apparatus

ABSTRACT

A climbing film heat exchange apparatus and particularly an evaporator is provided wherein a turbine is mounted on the shaft of the evaporator so that it is not necessary to provide a fluid seal on the shaft and, in some embodiments, the heat employed to drive the turbine also serves as part or all of the heat supplied to the apparatus for the heat treatment. In some embodiments of the invention wherein a hydrocarbon fluid is employed and it is desired to recover water, the water of combustion is recovered as part of the desired product.

SUMMARY OF THE INVENTION

The present invention relates to a climbing film apparatus and is animprovement on my prior patent, namely, U.S. Pat. No. 2,866,499.

Climbing film heat exchange apparatus is known from the above notedprior patent and others and, in general, such equipment is employed forprocesses wherein a portion or all of the liquid is evaporated althoughthe devices are of general utility and can be used in any applicationfor the heat exchange treatment of fluid and particularly fluids whichare difficult to handle in conventional heat treating apparatus such asviscuous fluids and suspensions.

The climbing film apparatus heretofore known require that a center rotorbe driven by means of an external motor and it is necessary to provideefficient fluid seals on the shaft. Further, the main application ofsuch climbing film devices is to serve as an evaporator in which case itis necessary to supply a substantial amount of heat to the apparatus.This is ordinarily done by means of heat exchange jacket wherein heat issupplied to the jacket to serve to evaporate a fluid climbing on theinside of the rotor housing. It is frequently difficult to supply asufficient amount of heat to accomplish the desired purpose.

In accordance with the present invention, an improved form of climbingfilm apparatus is provided wherein a turbine is mounted directly on theshaft of the rotor and a fluid, ordinarily a hot gas or vapor, is passedthrough the apparatus to drive the turbine. Since the drive is developedon the inside of the apparatus, it is not necessary to provide fluidseals on the shaft, greatly simplifying the equipment.

A further advantage of the present invention is that the gas whichdrives the turbine is ordinarily hot so that in some embodiments of theinvention the heat from the driving fluid also serves to heat thematerial being treated so that it supplies all or at least a part of theheat necessary for the treatment. Thus, the necessity of supplying heatfrom an external source to a heat exchange jacket is greatly reducedand, in many instances, all of the heat can be supplied by the drivingfluid.

In accordance with another embodiment of the invention, heat suppliedthrough the jacket vaporizes a portion of the fluid being treated andthis vapor drives the turbine.

The device of the present invention is more efficient than existingunits and accomplishes the same throughout as plants many times itssize. It is completely practical to build the units in a large range ofsizes from small household units to large industrial units.

Since the unit can be made in small sizes, it is completely practical tomake units wherein one or more of the units could function in thehousehold for purifying water for reuse as well as supplying hot water.In one contemplated use, the waste water from a household could besegregated into two or more categories with a separate unit serving topurify each of the individual water sources for reuse.

In industrial plants, the device can be made in modular form so thatmany small units could be hooked together, obviating the need forrunning at or near full capacity. In other words, if only a smallcapacity were called for, a few of the units could be operated while atmaximum capacity called for, all of the units could be put on stream.

An energy source is suitable for use with the present invention. Forexample, waste steam from nuclear energy electrical generation orhydrocarbon fuel.

The device of the present invention can be used with a variety of feedstocks and it is not required that the feed stock be pretreated. Thedevice of the present invention is particularly suited for thedesalination of water wherein most of the water from a brine can beextracted, leaving an extremely concentrated brine which is suitable foruse in the chemical industries. Since the range of feed materials is sogreat, there are substantial advantages of using the present inventionfor desalination over other well-known techniques such as ordinaryvacuum distillation or reverse osmosis. In this connection, the unitmakes an excellent source of fresh water for ships or for isolatedcommunities.

In some embodiments of the invention, the unit can be operated at lowtemperatures so that heat sensitive materials such as milk can bepasteurized without scorching or other materials such as natural waterscan be treated without destroying plankton or other organic life in thewater.

The device of the present invention can be used for the separation ofharmful chemical solids from various liquids and is excellent in theclarification of sewage water for industrial use.

In many instances, the unit is used for the desalination of water sothat the desired product is the water itself. In such cases, one canutilize a hydrocarbon fuel for running the unit and supplying heatthereto and the water produced by the combustion of the hydrocarbon fuelwill be recovered as part of the water which is desired as product.

The device of the present invention can be used with superheated waterin which case the water would be flashed off and the device of thepresent invention allows accurate control so that the device is muchmore efficient than conventional flash evaporators.

In many instances, valuable inorganic materials can be recovered fromthe unit such as the chlorides, sulfates and carbonates of variousmetals.

Only a few typical applications have been mentioned and the device isone of broad application.

Various other objects and features of the invention will be brought outin the balance of the specification.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a climbing film apparatus having a turbine atthe top for driving the shaft of the rotor from vapor developed withinthe apparatus.

FIG. 2 is a partial sectional view of a climbing film apparatus whereinan axial compressor and turbine are provided on the rotor shaft withmeans for directly supplying heat in the form of a flame between thecompressor and the turbine.

FIG. 3 is a sectional view of an apparatus somewhat similar to FIG. 2except that the turbine is mounted at the upper end of the rotor shaft.

FIG. 4 is a partial sectional view of a device wherein the effluent gasfrom the turbine is passed through the heat exchanger shell rather thandirectly through the body of the film climbing apparatus.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to FIG. 1, the evaporator includes a cylindrical shell 5having a shaft 7 mounted for rotation at the center thereof on the upperbearing 9 and a lower bearing 11. Mounted on shaft 7 are imperforaterotor blades 13 which have a very small clearance with the shell 5. Aheat exchange jacket 15 is provided outside of shell 5 with an inlet 17and an outlet 19 for the heat exchange fluid. In the embodiment shown,the jacket is divided into two portions by means of partition 21although a single chamber or more than two chambers may be employed inthe heat exchange jacket. If more than one chamber is employed,obviously additional inlets and outlets will be required for the heatexchange fluid such as the one shown at 23. Heat is supplied to thejacket in the form of a heated fluid, ordinarily a heated high boilingliquid.

Near the bottom of the chamber formed by the shell 5 is an inlet 25 forthe liquid to be treated and near the top of the chamber is an annularspace 27 for the collection of the treated liquid, the annular spaceleading to a discharge pipe 29. Vapor which arises from the treatmentwill be discharged upwardly through the port 31. It will be recognizedthat the parts heretofore described are largely in common with U.S. Pat.No. 2,866,499 so that various construction details have been omitted.

In accordance with the present invention, shaft 7 also carries turbineblades 33 which are disposed in an enlarged chamber 35 formed on top ofthe discharge port 31. Thus, vapor passing upwardly through the chamber31 impinges on the turbine blades 33 rotating the shaft 7. Effluentvapor is taken off through the outlet port 37.

In this embodiment of the invention, the vapor generated by the actionof the heat in the jacket 15 serves not only to provide the necessaryheat for the evaporation of a portion of the liquid which enters throughthe inlet 25 but also the vapor thus driven off serves to drive theturbine 33 and shaft 7 so that it is not necessary to provide a separatepower source for driving shaft 7, greatly simplifying the equipment,particularly in the elimination of a vapor proof seal at the bottom ofthe shaft.

In many instances, hot combustion gas which is used to drive the turbinecan be brought into direct contact with the liquid to be treated withoutcontaminating the liquid. This is particularly advantageous since directcontact between the liquid to be treated and the hot combustion gasprovides a very efficient heat transfer. Suitable equipment foraccomplishing this is shown in FIGS. 2 and 3.

Referring now particularly to FIG. 2, shaft 41 is mounted for rotationin lower bearing 43, the shaft 41 carrying the usual blades 45 and beingmounted in a cylindrical shell as heretofore described. An inlet 47 isprovided for the liquid to be treated. The bottom of the apparatus isprovided with air inlets 49 and shaft 41 carries an axial compressor 51and, spaced therefrom, are turbine blades 53. A burner 55 is providedbetween the compressor and the turbine and is supplied with a suitablefuel, such as gas or oil, from line 57. The operation is as previouslydescribed except in this case the hot combustion gas drives turbine 53and after leaving the turbine, passes around baffles 59 and then passesthrough chamber 61 where it comes in direct contact with the liquidbeing treated. A heat exchanger shell 63 may or may not be necessarydepending on whether liquid being treated requires more heat than issupplied by the burner 55 and, in some instances, the heat exchangershell 63 can be used for a cooling fluid in case less heat is requiredfor the evaporation than is required to drive the turbine.

The embodiment of FIG. 3 is very similar to that of FIG. 2 except thathere shaft 71 is mounted for rotation on the bottom bearing 73 and thetop bearing 75 and carries the usual blades 77 mounted for rotationwithin the shell 79. In this instance, the compressor blades 81 aremounted at the bottom of the shaft 71 and the turbine blades 83 aremounted at the top of the shaft. The burner 85 is mounted above thecompressor 81. The other parts are as heretofore described and theoperation is believed obvious. Air from the compressor 81 is burned inthe burner 85 and the exit gas after passing over the blades 77 in thechamber 79, drives the turbine 83.

In many instances, it is desired to provide internal combustion fordriving the shaft and supplying the heat for the evaporative process butit is undesirable to have the hot gas make direct contact with theliquid being treated. Further, in some instances, the passage around thecenter rotor provides a constriction on the passage of gas and it isdesirable that at least some of the gas be diverted from the chamber inwhich the fluid is being treated. In FIG. 4 there is shown an internalcombustion device which provides for the reduction or even eliminationof contact between combustion gas and the liquid being treated. Thedevice is substantially the same as is shown in FIG. 2 except for thepassage of gas after it leaves the turbine. In this instance, thecompressor 85 and turbine 87 are mounted on shaft 89 with the burner 91located between the compressor and the turbine. The jacket around thecylindrical chamber 93 includes an outer shell 95 with a series ofbaffles 97 therein forming a chamber 96 for the passage of heat exchangegas. At the outlet of the turbine, passages 99 leading from the turbineto the heat exchanger permit gas to leave the turbine and enter the heatexchanger, while the passages 101 at the top of the heat exchanger serveas a hot gas outlet. With this structure, most of the hot combustion gasdoes not come into direct contact with the liquid being treated butinstead passes through the chamber 96 and serves to heat the fluidclimbing wall 93 without being in direct contact with the fluid. Inthose instances where it is important that none of the combustion gascome into contact with the fluid being treated, shaft 89 can be providedwith a rotary seal directly above turbine 87 so that all of the gas canpass through the chamber 96 and not come into contact with the fluid.

Although certain specific embodiments of the invention have been shown,it will be understood that these are for purposes of illustration onlyand that the invention is not limited to these specific embodiments.Thus, many changes can be made from the exact structure shown withoutdeparting from the spirit of this invention.

The turbine and compressor are largely shown in diagrammatic form inthat the stators have been omitted and only a single stage is shown.

Although the device has been described primarily as an evaporator, itcan be also used for other purposes such as heating without evaporationand dilution by suitably adjusting the feed stocks and heat balance.

We claim:
 1. In a thin film climbing heat treating apparatus of the typehaving an annular chamber with a shaft having a plurality of flat bladesextending radially from said shaft, mounted for rotation within saidchamber and requiring means to drive said shaft, the improvementcomprising a turbine mounted on said shaft and spaced from said flatblades and means for causing a fluid to flow upwardly through thechamber past said flat blades and then through the turbine therebycausing said turbine to rotate said shaft.
 2. The structure of claim 1having in combination:a. a turbine mounted adjacent to the top of saidshaft; b. means for introducing a liquid near the bottom of said annularchamber; c. at least one jacket around said annular chamber and d. meansfor supplying heat to said jacket from an external source whereby aportion of said liquid is evaporated by heat supplied from said jacektand the vapor therefrom is utilized to drive said turbine.
 3. Thestructure of claim 1 having an axial compressor mounted near the bottomof said shaft:a. a turbine spaced from said compressor mounted below theblades on said shaft; b. means for introducing air below saidcompressor; and c. means for introducing a fuel between said compressorand said turbine.
 4. The structure of claim 1 having a compressormounted near the bottom of said shaft and a turbine mounted near the topof said shaft with said blades between said compressor and saidturbine;a. means for introducing air below said compressor; and b. meansfor introducing fuel between said compressor and said blades, wherebysaid fuel burns and the combustion products pass over said blades andinto said turbine.
 5. A structure in accordance with claim 1 having avapor jacket surrounding said annular chamber;a. a compressor mountednear the bottom of said shaft; b. a turbine mounted below said bladesbut spaced from said compressor; c. means for introducing a fuel betweensaid compressor and said turbine; and d. baffle means for deflecting aportion of the combustion gas from the burning of said fuel whereby aportion of the combustion gas passes over said blades and the balance ofsaid combustion gas passes through said vapor jacket out of contact withsaid blades.